1. Field of the Invention
The present invention relates to the field of construction and installation, especially the field of installing electrical insulators, and especially the field of installation and use of electrical insulators in power transmission and above ground power transmission.
2. Background of the Art
In the above-ground transmission of electrical power, whether high voltage or low voltage, it is essential to have the physical transmission lines separated from the above-ground supports. Without that physical separation between the lines and the supports, there are actual and potential problems of power loss, inadvertent power transfer to the support, accidental fire and electrical shortage hazards, and other issues relating to inappropriate transmission of power away from the power lines to the support or objects around or in contact with the support.
The separation between the support and the line is maintained by an insulator on the support and carrying the power line or cable. Where there are multiple lines, the insulators also separate the individual lines from each other.
The insulators are usually put on the supports (e.g., poles, stanchions, walls and the like) during construction. When poles are used, it is possible to place the insulators on the poles before the poles are planted or erected, and the lines are then placed on the insulators after the poles are in place. It is important that the insulators be properly aligned with the supports so that tensions and stress on the support caused by the weight of the lines (and any additional weight and stress added by ice, wind, animals on the lines and the like) are minimized and appropriately aligned. Any stress should be received by the insulator and the support in an optimized vector. Improper alignment of the insulator and its connection to the support can cause excessive stress and wear on the system and reduce its safety and endurance.
The insulators are typically placed on poles by placing a jig against the pole and drilling holes in the pole through alignment holes in the jig. The insulator is then attached to the pole through the holes with screws, bolts and the like. The jig may consist of little more than a fiat or curved plate with guide holes therein that is held by hand over the pole, and a drill cuts out holes in the pole after passing through the guide holes. The alignment of the holes and the jig to the surface of the pole can be less than ideal, and alignment can vary significantly between poles and even on the same pole where multiple insulators are present.